I've gone sour! using sourdough

[Microscopist]

Bees have been occupying most of my spare time but I've been quietly brewing.

I thought I'd try using my sourdough to brew - originally my plan was to sour part of the mash then add it to the boil and ferment normally but my yeast culture didn't make it so I pitched sourdough starter as well. It's come out damned drinkable.

My sourdough was started using cultured buttermilk and white flour and kept going on 50:50 flour water for about 4 months before I tried this.

Sour mash -

0.5kg Pilsner malt mashed 2 hours at 65C, strained and 100g sourdough starter added 1 week before brew day.

main mash
Pilsner malt 1.25kg
Maris otter pale malt 0.5kg
Crystal rye 150g

Mashed at 65C

Hops
Herkules 10g 90min
Cluster 15g 90 min
Cluster 10g 0 min
12l

Hydrometer broken so no OG

Kegged after 3 weeks - primed with 100g sugar. Slight nail varnish aroma when I opened the fermentation bin, pink powdery pellicle but I thought what the hell...

4 weeks later taste ok but very thin

9 weeks - went on holiday came back to broken heating - house had been at around 35C for a week. Much gas production, keg bottom had ballooned out and tap had leaked around 2 pints over the floor.

14 weeks - just had a pint - it's fantastic, sourness up front but the malt and hops really come through.

Chances of this being toxic?

 

[MrFancyPlants]

You balloooned the bottom of the keg? Can we see a picture? No blowoff valve? I think it is very small likelihood of being toxic, especially if it tastes good.

I wouldn't put it in a bottle for quite a while, for the risk of bottle bombs, but if it works it works.

 

[Microscopist]

The 'valves' on my kegs are basically a bit of tight vinyl tube on a nipple with a small hole in the lid - they regularly balloon ( makes me wonder if I should change makes ).